Ahmed Anas, Ilyas Suhaib Umer, Noshad Nawal, Alsaady Mustafa, Abdulrahman Aymn, Mahfouz Abdullah Bin, Ali Abulhassan
Industrial and Systems Engineering Department, University of Jeddah Jeddah 23890 Kingdom of Saudi Arabia.
Chemical Engineering Department, University of Jeddah Jeddah 23890 Kingdom of Saudi Arabia
RSC Adv. 2025 Feb 24;15(8):6100-6109. doi: 10.1039/d4ra08312a. eCollection 2025 Feb 19.
The addition of nanoparticles into conventional fluids changes their thermophysical properties, such as thermal conductivity, viscosity, density, and specific heat capacity (SHC). While different nanofluids' thermal conductivity and viscosity are studied extensively, only a few experimental studies are subjected to SHC properties. It is important to investigate the SHC of nanofluids to understand their thermal aspects, particularly where the literature shows ambiguous results for the SHC of nanofluids. This study measures the SHC of diamond-based thermal oil nanofluids using differential scanning calorimeter (DSC) at varying nanoparticle concentrations of 0.25, 0.5, 0.75, and 1 wt% and a temperature range of 35-80 °C. The SHC of these nanofluids increased with temperature and decreased with an increase in nanoparticle concentration with a maximum SHC decrement of 8.25% at the highest 1 wt% concentration. The classical models are proved to underpredict the SHC of diamond-thermal oil nanofluids, as many nano-scale phenomena are not considered in these models. Therefore, a new multivariable correlation is also proposed for predicting the SHC of diamond-thermal oil nanofluids, exhibiting a good agreement with the experimental data with an of 96.35%.
在传统流体中添加纳米颗粒会改变其热物理性质，如热导率、粘度、密度和比热容（SHC）。虽然对不同纳米流体的热导率和粘度进行了广泛研究，但对比热容特性的实验研究却很少。研究纳米流体的比热容对于理解其热学特性很重要，特别是在文献中纳米流体比热容结果不明确的情况下。本研究使用差示扫描量热仪（DSC）在纳米颗粒浓度为0.25%、0.5%、0.75%和1 wt%以及温度范围为35 - 80°C的条件下测量了金刚石基导热油纳米流体的比热容。这些纳米流体的比热容随温度升高而增加，随纳米颗粒浓度增加而降低，在最高1 wt%浓度下比热容最大降幅为8.25%。经典模型被证明低估了金刚石 - 导热油纳米流体的比热容，因为这些模型没有考虑许多纳米尺度现象。因此，还提出了一种新的多变量关联式来预测金刚石 - 导热油纳米流体的比热容，与实验数据具有良好的一致性，拟合优度为96.35%。
